Mods in sig. Car dyno'd at 338 RWHP! Car is running way too rich. 12:1 at idle, and pegged the wideband at 9:1 at WOT. Program from PCM For Less, also pulling 8 degrees of timing at WOT. What do I do? I am extremely disapponted. Making less power now then when I just had the blower!

 

My first question is why don't I see anything fuel related in your signature? The next question is, at WOT when timing is retarded, what is the knock signal, does it show knock from the knock sensor?

What recently changed? You said "now then when you just had a blower" Look at what changed since you just had a blower and check each one. If it was the programming, then try to find a pcm in the condition yours was in before you had it programmed, swap it in and see if that cures the problem.

I would put serious thought into your fuel system if your going to run a blower which by the way right now is putting out (even in the crappy condition your running right now) about 400 to 420 hp. A better regulator and filter are a good start. I would monitor fuel pressure and maybe consider a better pump as well. Consider the formula for injector sizing...... HP= flow rate * 8 injectors * .8 (duty cycle) divide that by 0.5 .

Now rearrange the formula for injector sizing....... Flow rate = Engine HP * 0.5 divided by 6.4 (8 injectors *0.8)

this formula yields 32# injectors for your engine which is near or above 400hp. That is if what you said about the 338 RWHP is correct. If your programming is one of the newly added items, it may have been programmed for a corrected injector flow rate. Even though your getting results that show your too rich, and that seems opposite from too small of an injector. That could be part of your problem.

BTW, don't ever buy ACCEL fuel injectors. I have heard too many horror stories using these.

 

Sounds to me like you just need a re-tune.
Do you have datamaster so that you can send Bryan some part throttle stuff and then send him your dyno sheets and he can probably get you much closer to your wot needs.
Mail order tuning is usually not even close on a blower car.

 

You're fuel system is FINE! As a matter of fact, too fine, since you're pig rich. Take a copy of the dyno run and send it with your PCM back to PCM for less. Or better yet, buy LT1 edit and get back on the dyno and do it right.

As for the timing, you could be experiencing false knock. I doubt it's real knock since you're not even close to being lean. Do you have an LT4 KM?

 

Thanks for the replies guys. First of all, the fuel system is the T-rex in-line pump that comes with the Vortech. The injectors are 42# Lucas injectors from Combination Motorsports. The newly added items are in the bottom of the sig, heads, headers, cam, 1.6 R/R , injectors, throttle body, and programming. Intake is port matched w/heads and TB. Heads were P/P with valve job and milled. Program was written by Bryan for the above mods with the FMU removed by Bryan. Fuel press. reg. is stock. Is that something I should really change? Can a program make that much difference in horsepower? I am also running autolite 106's. Car temp stays at about 170. I am up a certain creek without a paddle because I have no way of tuning my own computer until I get my cable from Andrew and then pray that the USB adapter will work with my computer. Any other comments and suggestions are welcome. What kind of horsepower should I be seeing so I know if I getting close? Thanks guys, Rob.

 

Don't touch the FPR.

YES! You are about 3.5-4 A/F ratio points off. Expect 40 horse or so when you get that ironed out.

 

So you guys think it's just in the programming, thats good. I was seriously expecting to see at least 425-450 RWHP with all the work I have into it. How far off am I once I get the tuning straightened up. What else is going to get me there besides more cubic inches or nitrous(which I would'nt even think about doing with the stock bottom end and a blower). Thanks for your replies and taking the time out of your day to help a fellow gear-head out, Rob.

 

I would almost guarantee it's more than that on the car in question.

ramermanz28 - have you talked to Bryan? If you send him the dyno info and the a/f curve I'll be he can get it a whole lot closer pretty easily.